It is known in the prior art that articles of manufacture may be supplied for sale in the retail trade within the pocket of a blister member mounted on and sealed to a backing card thereby to encase the article in its individual package. The material of the blister member preferably is transparent so that the article within the pocket may be viewed before purchase.
In the overall packaging operation, the individual blister members normally are formed from plastic sheet material, such as polyvinylchloride, and processed under heat and pressure within a mold. The individual blister members of a row including a number of blister members in side-by-side orientation thereafter are moved from the forming equipment to a conveyor providing an equal number of supports such as cup-like openings for receipt of the blister members with the pocket upwardly exposed. The conveyor is advanced in stepped fashion to receive the blister members seriatim within the supports and move these blister members to and through various stations at which an article is loaded in the pocket and encased by sealing the backing card to the blister member. The backing card supports the blister member and vice versa along a flanged surface extending outwardly at the opening to the article receiving pocket.
In one prior art apparatus, the blister members are moved from the forming equipment to the conveyor by passage along a chute. Such movement is by gravity fall. This operation is not without problems. A major problem develops through build-up of static electricity on the blister members resulting in possible "hang-up" of the blister member in the chute to the conveyor. Thus, less than a complete complement of blister members are received by the conveyor. Even the use of electrostatic dissipaters has not solved this problem, which if severe, often times requires shut-down of equipment. In an attempt to better assure movement of the blister members by the force of gravity without "hang-up" along the chute, the thickness of the sheet material stock has been maintained at about 5 mils; whereas, it is clear that the packaging industry could realize a material cost savings by the reduction of thickness of the sheet material stock to a permissible and operable thickness of 4 mils or even less. This, however, has not been possible for a reduction in the thickness of the sheet material would have the result of aggravating the problem of "hang-up". Even though the cost savings, considered a product output which may be millions of units, may be substantial, it is likely that the cost savings would be negated by losses sustained in down-time of equipment, for example.